Wildfire impacts to aridland stream chemistry across a hydroclimatic gradient
Abstract
Increases in the frequency, extent, and severity of wildfires have the potential to have long-lasting and wide-ranging effects on watershed processes and water quality. However, understanding of these effects remains largely phenomenological, with a focus on short-term or localized effects. Without long-term and large-scale data syntheses, much-needed mechanistic and predictive insights remain elusive to plan for a future of increasing wildfire impacts on ecosystems and water supplies. We analyzed long-term stream chemistry records from 33 watersheds in the southwestern US, where water supplies are particularly vulnerable to changing quality and quantity. The study encompassed a range of hydroclimatic regimes, including both snowmelt- and rain-dominated, as well as Mediterrannean, monsoonal, and winter frontal regimes. Watersheds encompassed unburned to recently, severely burned areas. We found that hydroclimate interacts with antecedent conditions to determine the timing of both wildfire and runoff generation, and that these drivers interact to determine the timing and severity of water quality impairment, as well as the duration and trajectory of biogeochemical change. Based on our findings, we present a conceptual framework organizing the potential mechanisms underlying wildfire effects on watershed biogeochemistry in aridlands, with the ultimate goal of predicting changes to watershed processes and water quality following observed and expected increase in wildfire in the Anthropocene.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2021
- Bibcode:
- 2021AGUFMGC21C..07W